1. Acquaintance,associate,companion,friend refer to a person with whom one is in contact. An acquaintance is someone recognized by sight or someone known, though not intimately: a casual acquaintance. An associate is a person who is often in one's company, usually because of some work, enterprise, or pursuit in common: a business associate. A companion is a person who shares one's activities, fate, or condition: a traveling companion; companion in despair. A friend is a person with whom one is on intimate terms and for whom one feels a warm affection: a trusted friend.3. familiarity, awareness.

c.1300, "state of being acquainted;" late 14c., "person with whom one is acquainted;" also "personal knowledge;" from Old French acointance "acquaintance, friendship, familiarity," noun of action from acointer (see acquaint). Acquaintant (17c.), would have been better in the "person known" sense but is now obsolete.